Topic: LED turn signal/running light question for the electrical fellas...

[Jinxracing]

I'm running aftermarket turn signals that use the "festoon" type of bulb, 39mm in length. To cut down on power consumption, I'm going to be running LED bulbs as replacements for the standard filament-type bulbs. I'd like to have these operate as running lights as well as turn signals. However, dual-intensity LED bulbs in this style don't seem to exist, so it looks like I have to choose one or the other: either dual-filament standard bulbs with their higher current draw, or run LEDs but have no running lights. 

I'm hoping that someone who's a bit more electrically experienced than me can give me some help. I'll be using this flasher by the way:

http://www.customled.com/PRODUCTS/FLASHER_RELAY/flasher_relay.htm

Perhaps have it default to "always on" instead of "always off" when the turn signals aren't in use? I'm in a bit over my head here...

[Master Ted]

Look at the dual density Radiantz LED Clusters. Just remove the guts of your turn signals and place the LED board in the casing with silicone.

http://www.customdynamics.com/motorcycle_led_bulbs.htm#Radiantz_LED_Clusters_

Another option is to convert your signals to an 1157 socket which I have done playing around with stock signals (pre front running light era) and have made it work. But, it's tight and the stock has to be drilled out to make room for another wire. You can then screw in the 1157 LED bulb.

These hardboard Randiantz have real skinny wires and obviously allows you to skip the socket switch step.

[TwoTired]

Is this for a CB750 K1, as in your avatar?  Did they have front running lights?  If they use the same wire diagram as the K0, then no.  Neither will the bar switches support running lights on the front.

In the Honda manual supplement for the K1-K4, it only lists a wire diagram labeled for the K4.  The K4 is running light capable.  But, the book leads me to believe that prior models were not.

Anyone have contrary info?

Cheers,

[Master Ted]

TT, he could tap into rear running light circuit in headlight bucket... addition load would be quite small with LED. 

[SD750F]

Jinxracing,

Fist I would not use a Festoon style bulb on any bike application. The nature of the connector interface is not the most reliable for a shake and vibration application. You should use a more robust conenctor type or you will negate the benefits of having a non filament bulb. And you would have a lot more options for a dual element LED...

As far as you flasher problem, I wasn't too sure you had one. Did you say that the flashers remained on and did not flash? Which flasher per your link did you buy? And be aware that the color codes the flasher uses do not match color to color the wiring in t=you standard Honda.

Scott

[Bodi]

There are no rear running lights, they are turn signals only.
The turn signal switches on early models don't have the contacts to shut the running light off on the signalling side. That makes the turn signals less effsctive especially in the dark as they would only change brightness not flash entirely off.
But you can do anything of course. A single LED lamp can be different brightness for two sources with 2 resistors and 2 diodes, the signal power goes througha standard diode to the bulb; the diode voltage drop won't dim it much. The running light power - ignition power on a bike without the stock wiring - goes through another diode and a resistor (probably 100 to 200 ohms, but you'll need to experiment) that provides less power and a dimmer bulb. The diodes isolate the 2 power sources, without them you''l have a mess. Only high-wattage LED units (with a single 1 or 3 watt LED) will have a problem with this dimming approach, they usually have a power regulator unit that will attempt to control the LED brightness over voltage fluctuations. I tried to make a simple schematic but my computer freehand drawing is double plus ungood.
The flasher suggestion has a problem in that many places ban non-red tail lights: only turn signals can be amber and must not stay on. Plus standard flashers power the lights through the turn signal switch, there's no "normally on" function. Paying a relative fortune for a "LED flasher" is silly when there are plenty of perfectly functional standard 3-terminal automotive flashers available MUCH cheaper.

[Master Ted]

many places ban non-red tail lights: only turn signals can be amber and must not stay on.

That's the only real obstacle. The dual color LEDs are too expensive for me and would require a clear lens which dosen't interest me. And, the thought of running additional light posts is a harlyfying thought.

I recently scored vintage Shoie hard bags and 500 mounting hardware I'll be reconditioning (I'm now using this bike for everything). I'm going to see what I can do to add very discreet lighting for both functions in LED.

Maybe I can borrow some lighting ideas from this guy:

[Jinxracing]

Thanks for the replies everybody.

The wiring for this project is completely from scratch; the bike had no wiring to speak of when I got it so I'm fine with making changes as needed as I build the harness.

Believe me, I'd LOVE to switch out these darned festoons for an 1157-style socket, but the housing for these signals just isn't large enough. I think I've found a solution:

http://www.customled.com/PRODUCTS/MAGIC_BLINKER/magic_blinker.htm

$40 a pair, but sounds like it'll do the trick. Bodi, are these Magic Blinkers just prepackaged versions of your diode/resistor suggestion?

[zanzara]

You could give these guys a try. Have gotten a few things from them and have been pleased with the results. Seem to have about anything you would need.

http://autolumination.com/1156_1157.htm

[Bodi]

"are these Magic Blinkers just prepackaged versions of your diode/resistor suggestion"

No, this does what you suggested at first - turning the flasher into normally on, flash off. It's essentially a relay (although it's electronic, much like the difference between mechanical and electronic regulators) that turns off the signal light when the flasher tells it to turn on... each one will require a power and ground wire as well as the "original" signal lamp wire from the harness. You will need an LED capable flasher as well, the stock thermal flasher won't work on the low control current to operate the "magic blinker".
This is actually a pretty neat device, bagger types could flash all the geegaw lights on one side with the blinker.
You could do it really easily with standard auto relays (one for each side) too. The main advantage of the Magic Blinker over an automotive relay is size. For LED use, a tiny reed relay (like these http://www.hascorelays.com/reed_relays_dip_sip_series.asp) would be about the same size and would handle LED current no problem.